Earth Footwear Kalso Lite Running Shoes

Earth Footwear, Kalso-Lite Lazer-K

Review, originally posted 2008-04-11 on

Style: Men’s
Sample Size: EU44 / UK10 / US10.5
Design: Earth Footwear (USA), Anne Kalso
Country of production: China
Weight per shoe*: 231 gr. (8.14828 oz.)
Thickness of sole*: Heel: 13 mm. (0.51181 in.). Front: 18 mm. (0.70866 in.)
Upper material: Japanese microfiber (complex combination of polyurethane and nylon)
Sock: Mesh
Lining: Lycra
Footbed lining: Post-consumer recycled plastic bottles
Outsole: E-max with latex at heel
Price: $109 (around €69 or £55, most likely more outside of the U.S.)

*Weight and thickness are always measured without insole when possible (since I usually recommend losing the insole, thus making the shoe more minimal). The weight is found using electronic scales from OBH that weigh down to 1 gram. The thickness is measured with a one-handed bar clamp. Thickness and especially weight are of course dependent on shoe size (See above).

The Product

In the 1970′s Danish Yoga instructor Anne Kalso (in Danish: Kalsø¸) invented shoes that turned the concept of a regular shoe around: the heel was low and the front was high. In Danish culture it became one of the symbols of the 70′s: alluding to the nonconformist part of society that was tired of the way things were going. However, Kalso suffered a lot of ridicule as well – the shoes were mentioned in a song mocking Danish bohemians, and Danish cartoonist Jesper Deleuran ironically noted: “Suitable for backwards mountaineering”. Later Kalso shoes completely disappeared from the Danish market that, like most other shoe markets, was convinced that big and clumsy heels made feet shout with joy.

However, the American company Earth Footwear has continued Kalso’s legacy. According to a Time article, Earth Shoes [as the company was called in the 70’s] owe their appearance in the U.S. to Jacobs’ [Raymond Jacobs, U.S. distributor of the footwear] wife Eleanor, who first came across them in a small Copenhagen shop.” They tracked down Anne Kalso and then it all began. Thanks to Earth Footwear the Kalso concept has spread around the world and is actuallyback in Denmark once more – only in a much more practical and fashionable design with a broader target group, which is kind of a very interesting story in itself.

Earth Footwear Kalso Lite Running Shoes

The original Kalso theory was that lower heels equal better carriage; that the Brazilian Indians, for instance, have an erect posture due to the heels sinking into soft terrain. Thus the shoes have a sole that imitates walking slightly up a hill (the front is 3.7 degrees higher than the heel). The concept is now called Kalso Negative Heel Technology and besides good posture the benefits should be better leg and calf toning, tighter thighs, firmer stomach muscles and better breathing (I will return to these claims in the next section).

The model reviewed here is the Kalso-Lite Lazer-K (grey). It comes in a recycled green box that includes biodegradable shoe bags, a note about the Earthshare project (register your shoes and support environmental and conservation organisations) and two pair of laces (grey and black/grey). It is definitely nice ethical packaging, though the shoes themselves are not entirely made from renewable materials (they are vegan, though). The Lazer-K is a men’s style, but there is a similar women’s model simply called Lazer.

Unboxing Earth Footwear Kalso Lite Running Shoes

The shoes themselves have many nice features: a wide front, a flexible sole, soft upper material and no Achilles supporter (the rear part is just soft fabric). They have laces for an extra tight fit, but you do not have to use them – you can just slip right into the shoes.

Back of Earth Footwear Kalso Lite Running Shoes

The shoes have a fairly thick insole that you can lose, but even without the insole the Lazer-K’s are the most thick-soled shoes reviewed so far. However, since the sole has such an extraordinary shape, they are still very interesting from a front foot runners perspective (the heel is not a problem here). And even though they are not precisely minimal shoes, they actually weigh exactly the same as the Vivobarefoot Aqua’s. So what will be really interesting is how they work in praxis.

Removable Insole in Earth Footwear Kalso Lite Running Shoes

Last thing to notice is the arch support, which will make most doctors happy, but may not be preferred by “almost-barefoot” runners. Personally, I am not very fond of anything that tries to support my movement when walking or running, since I am convinced that my feet already work perfectly and that shoes should only provide a thin unnoticeable layer between my feet and the asphalt or pebbles underneath.

Tread thickness of Earth Footwear Kalso Lite Running Shoes

Finally, remember that the Lazer-K will be reviewed from a minimalist philosophy. There are segments that will use the shoe for completely different reasons but here the focus will be on their barefoot performance.


One of the first things that surprise you is the weight of the shoes. They are the same size as my three old motion controlling New Balance shoes, but on average the Lazer-K is 50 grams lighter. This is a nice result and it can definitely be felt when walking around in them.

The next thing I want to mention is the fitting. It is very easy getting into them. You can just pull them on like socks – the laces are unnecessary (but help making the shoes look good). That is when walking. When you run the laces come in handy and are in fact very obligatory for a secure fit.

Side view wearing Earth Footwear Kalso Lite Running Shoes

Overall the upper material is very comfortable and the lack of an Achilles supporter (as mentioned the rear part is just soft fabric) is very nice because it makes your foot the master and not the shoe. However, the shoe has an arch support, which on the other hand removes freedom of movement. It is actually something you will definitely notice when running in the Lazer-K’s – especially if you are used to flat soles. Not only did it give me blisters; it also reminded me of my old running shoes that tried to keep my foot in place all the time. The blisters disappeared quickly, but the domination of the arch support was always in my mind. I should of course repeat the fact that most doctors seem to prefer arch support, and if you are flat-footed there are some important aspects you have to consider and that may want you to choose arch support. Also, since the Lazer-K’s have quite a thick sole the arch support helps you balance.

But again, I am reviewing the Lazer-K’s from a minimalist philosophy and my thoughts are like this: keeping balance strengthens you. A somewhat weak, thin-soled minimal shoe will make you better at keeping balance naturally, since your foot is in charge. A motion controlling shoe will do the opposite and could end up making you foot weak instead. However, when a shoe has a thick sole it risks becoming too unsteady, so my advice to Earth Footwear would be to lose the arch support and make the sole thinner instead (10 mm. (0.3937 in.) could actually be cut away at both the heel and the front). They could still keep the sole shaped like a slope – just a slope that is closer to the ground overall. This is of course only interesting for them if they wanted to make a Kalso minimal shoe. The segment that wants a nice soft and bouncy sole is by far the biggest. Still.

The Lazer-K’s are not trying to control everything, though. Far from. It is only the arch support we are talking about. Other aspects of the shoe provide freedom, like the missing Achilles supporter and the wide front that works very well and keeps your toes happy. So if you just went from a regular shoe to this one you have made a lot of progress.

Front view wearing Earth Footwear Kalso Lite Running Shoes

Now for my experience with the sole, which is the most interesting part of the shoe – and the part that could potentially upset most barefooters, making them underline that it is too thick for “almost-barefooting”. I too had some concerns, but the fact that the heel was quite thin, compared to other shoes, persuaded me into trying them out. That, plus the fact that the shoes were exactly the opposite of others: they keep your front feet up.

So how did they work? Well, the first run truly amazed me. Yes, the Lazer-K’s felt a bit clumsy compared to a couple of water shoes, but they actually work for front and mid foot landing. I suspect new barefooters would perhaps even feel that the Lazer-K’s make front foot landing easier. You really have to lean over backwards (pun intended) in order to heel strike.

The sole is quite flexible. It actually reminds me of my old Nike Free 5.0 (just turned around). The deep grooves do enhance agility a bit, in my opinion, and provide a firmer and longer lasting grip, and I think they are quite necessary due to the thick front sole. A regular running shoe is thinner at the front and hence flexibility is not a big problem, but when the front is as thick as on the Lazer-K’s something has to be done in order to escape the fate of the MBT shoe.

Tread pattern of Earth Footwear Kalso Lite Running Shoes

Flexibility of Earth Footwear Kalso Lite Running Shoes

Walking in Lazer-K’s is another experience. In fact they make Fox Walking (unfairly shortened to: landing on the side of your front feet and sliding inwards) quite impossible. The sole is too thick for a natural glide. Hence you will most likely decide just to heel strike, which is completely fine and natural when walking. The impact is not as great as when running and a bit of heel striking will strengthen your bones.

When walking in the Lazer-K’s you quickly notice that something happens to your calves and Achilles tendons. They are stretched more than you are used to. This should be one of the benefits that could help people with short calves or rigid tendons. And I reckon it is actually true. The soreness I felt in the back of my legs verifies that some degree of stretching took place. Then a natural question would be: is this stretching beneficial to people without calve problems? Well, you could turn the question around and ask: are big or high heels beneficial? Do they not shorten your calves and tendons and make stretching exercises a must? I guess I would have to return to my point of departure: a sole should be exactly midway – because that’s how your feet are shaped: flat, but flexible. Once more we reach the issue of modern urban surfaces. Are they not too flat? Your so-called flat feet should meet unequal surfaces regularly and that is impossible if you live in a city. And I guess this is the chain of reasoning that makes some innovating companies want to create unequal soles instead – to imitate a natural surface. However, in my opinion, there is a greater chance that this kind of footwear will provide more unsuitable monotony than if you just walked around barefoot in a city. It will take away your freedom of adjusting to your environment (not in an evolutionary sense) – and make it difficult to use natural techniques that provide variation (like Fox Walking or front or mid foot landing). So it is a matter of how you see it. The Lazer-K’s do not make front foot landing difficult, though, but they pretty much force you to walk the same way all the time.

This short discussion in mind I would still recommend Earth Footwear – especially if you are used to walking in shoes with big heels. They provide a nice supplement for your calves and tendons, and I think the reasoning behind them (the “sinking into the ground” philosophy) is much better than the reasoning behind regular shoes with high heels (if there really is one). Also, keep in mind that when running the shape of the sole is not as big a problem. You will still feel soreness in the beginning (even though you are already used to barefoot running), but since you only use your front feet you do not undergo the whole “rolling upwards” motion.

Toe flexibility of Earth Footwear Kalso Lite Running Shoes

Let me also turn to the initial claims by Earth Footwear: good posture, better leg and calf toning, tighter thighs, firmer stomach muscles and better breathing. Regarding posture I would agree. If you have a tendency to “collapse” the shoes will make leaning forward a bit harder. Regarding leg and calf toning I would also agree – if you are used to regular shoes. If you already use minimal shoes or simply walk or run barefooted there is no discernible improvement – though there is in fact a bit of exercise when walking (the “hill walking” imitation). I felt no improvement in my abdominal muscles and no effect on my breathing, but if you are in bad shape the bit of exercise the shoes provide could possibly help you.

Finally, the shoes offer average to good breathability, no water repellency, but very good durability. They still look quite new and regarding quality they are great!


[Rated: 5/10 Toes]

The Lazer-K’s are a nice alternative or a good supplement to regular shoes if we consider walking. What surprised me the most, on the other hand, is how suitable they are for front foot running. If we omit the arch support experience I actually looked forward to my runs in these shoes. I wouldn’t use them as my only running shoe for a longer period, though.

It is hard to categorise them on the minimal shoe scale, since they are not exactly sock-like. But they provide something else. Like the Vivobarefoot Aqua’s I would say to a future barefoot runner: the Lazer-K could be a good first minimal shoe. It can be burdensome to go from a regular running shoe to a minimal shoe and the Lazer-K could provide an easier transition. Shoes like these could help runners start their barefoot journey. And if you have been used to unsuitable high heels for ages, the Lazer-K will also help you stretch those calves and tendons when walking. One important note, though: do not overdo it! There is a big difference from landing on a high heel to suddenly having the whole shoe turned around. Ease into the Lazer-K experience and as always: listen to your body.

At last, the Lazer-K’s actually look great (though it is of course subjective). People around me for once thought I was wearing nice shoes instead of those “weird shoes” (read: minimal shoes) I often wear. Little did they know that I was wearing a concept shoe in disguise. So the Lazer-K’s also help you avoid a lot of inquiring eyes.

What could be interesting in the future was a completely minimal Kalso shoe. I would like to learn how they performed with thin soles that still sloped a bit.

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